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821.
The v. Euler-Liljestrand mechanism is of specific importance in the development of cor pulmonale following alveolar hypoventilation. In the functionally induced rise of the pulmonary vascular resistance the role of vasoactive agents is neglegible. Pharmacological experiments point to an inhibition of the so called beta-receptors in the presence decreased alveolar PO2 and a rise in alveolar PCO2. The v. Euler-Liljestrand mechanism may be elicited by an inactive beta-receptor mechanism. Changes in intrathoracic and alveolar pressure play an important part in the development of congestive heart failure in patients without manifest pulmonary hypertension. The modifying effects on the pulmonary circulation are shown by means of pressure curves recorded from the right ventricle. It is recommended what a distinction be made between cor pulmonale and cor emphysematous in determination of the predominant pathophysiological mechanism, responsible for congestive heart failure. 相似文献
822.
823.
Fentanyl is devoid of major effects on coronary vasoreactivity and myocardial metabolism in experimental animals 总被引:6,自引:0,他引:6
Experiments were designed to determine the effects of fentanyl on coronary vascular tone and energetic state of the heart. Both arterial and arteriolar responses were assessed; particular attention was directed to epicardial vessels. Four experimental methods and three animal species were used. Isolated canine coronary artery rings with and without endothelium were suspended in organ chambers, and changes in their tension were measured. Fentanyl (100 ng/ml) had no effect on resting tension of unstimulated rings on a contraction evoked by serotonin 10(-8) to 10(-4) M. In rings with endothelium, the opioid had a minimal depressant effect on the contractile response to phenylephrine. Tension of vessels precontracted with serotonin (3 x 10(-7) M), or phenylephrine (10(-5) M) was unchanged following fentanyl at 10, 30, 70, or 150 ng/ml. Computerized quantitative angiography was used in intact pigs anesthetized with ketamine to determine the effects of fentanyl on coronary artery diameters of vessels with or without endothelium. Intravenous fentanyl 50 and 250 micrograms/kg had no effect on vessel diameters. Isolated perfused rat hearts were used to assess fentanyl effects upon coronary flow and arteriolar tone and upon myocardial energy state. Coronary blood flow was not altered by fentanyl (100 ng/ml) and was unchanged following washout of the drug. The heart maintained a normal energy status prior to and following fentanyl treatment. These data demonstrate that, under the conditions tested, fentanyl is devoid of major effects on the coronary circulation and upon myocardial metabolism. 相似文献
824.
825.
特异性阿片受体μ,κ和δ拮抗剂在IL—1β所致体温升高中的作用 总被引:2,自引:0,他引:2
下丘脑视前区前部(POAH)是经典的体温调控中枢,并存在有阿片受体。本研究旨在了解细胞介素IL-1β所致的体温升高是否与产生的内源性阿片有关,以及通过何种类型的阿片受体介导此升体温效应。研究使用雄性S-D大鼠,于自由状态下向其POAH区微量注射IL-1β,注射前30min先向该区分别注射特异性阿片受体μ的拮抗剂CTAP,受体κ的拮抗剂nor-BNI,受体δ的拮抗剂NTI以及通常的阿片受体拮抗剂Nal,用Sal做对照。结果:IL-1β单独给药引起剂量相关的体温升高;经CTAP或者NTI处理后,使IL-1β所致的体温升高作用减弱;Nal能完全阻断IL-1β的升体温效应;而nor-BNI对IL-1β的升体温效应无影响。 相似文献
826.
SUMMARY In a 69-year-old man with recurrent rigors after an episode of diarrhoea due to Salmonella enteritidis, investigation failed to reveal the presumed abscess. He died 5 weeks after initial presentation despite appropriate antibiotic therapy. Postmortem examination revealed ruptured cerebral mycotic aneurysms as the cause of death; a myocardial abscess was found at the site of an infarct scar. 相似文献
827.
Halothane 1.5 MAC, isoflurane 1.5 MAC, and the contractile responses of coronary arteries obtained from human hearts 总被引:3,自引:0,他引:3
E Villeneuve G Blaise J C Sill M J Guerard J Buluran D Girard 《Anesthesia and analgesia》1991,72(4):454-461
Active vasoconstriction of epicardial coronary arteries can cause myocardial ischemia in patients with coronary artery disease. Relief of vasoconstriction can improve blood flow to the heart. The purpose of this study was to determine if 1.5 MAC halothane and 1.5 MAC isoflurane would each attenuate contractions evoked by three putative mediators of coronary constriction in coronary arteries removed from the hearts of human beings. Hearts were obtained in the operating room from five patients undergoing cardiac transplantation and from six brain-dead patients undergoing organ donation procedures. Coronary arteries were dissected free, cut into rings, and studied in organ chambers. Endothelium-dependent relaxations to 10(-6) M bradykinin were examined; they indicated a variable degree of endothelial dysfunction in vessels used in the experiments. Contractile responses to 40 mM KCl were tested and were used as control contractions. Contractions evoked by serotonin, histamine, and prostaglandin F2 alpha were measured and were expressed as a percent of contractile responses evoked by 40 mM KCl. Halothane depressed the agonist-induced contractions. Maximal contractile responses to serotonin were 130% +/- 28% in untreated rings and 63% +/- 10% in rings exposed to halothane (P less than 0.03). Responses to histamine were 183% +/- 46% untreated and 121% +/- 26% during halothane administration (P less than 0.05), and responses to prostaglandin F2 alpha were 227% +/- 42% untreated and 148% +/- 18% with halothane (P less than 0.05). Isoflurane had no effect on contractions. The results demonstrate that 1.5 MAC halothane, but not 1.5 MAC isoflurane, attenuates contractile responses evoked by putative mediators of coronary vasoconstriction in coronary arteries removed from the hearts of human beings. 相似文献
828.
829.
830.
Watt AC; Ackerman LV; Windham JP; Shetty PC; Burke MW; Flynn MJ; Grodinsky C; Fine G; Wilderman SJ 《Radiology》1986,159(1):39-42
To evaluate its potential for differentiating benign from malignant breast lesions, digital subtraction angiography of the breast (DSAB) was performed in 23 women with mammographic evidence of disease, and the results were compared with surgical biopsy findings. The DSAB technique employed breast immobilization with modest compression and bolus injection; following the injection of contrast material, 30-40 sequential subtraction images were obtained over a 5-minute interval. The average technical settings were 50 k Vp and 10 mAs, resulting in an estimated radiation dose to the breast of 0.05 mrad (0.5 mu Gy) per exposure. DSAB consistently demonstrated retention of contrast material and abnormal vasculature in malignant lesions but not in benign lesions. In the 22 breast lesions for which there was histopathologic correlation, DSAB correctly categorized eight of nine malignant and 11 of 13 benign lesions. Although this series is small, the initial results of DSAB suggest its potential for differentiating benign from malignant lesions. 相似文献